Overhead valve means for internal combustion engines



May 8, 1956 A. c. SAMPIETRO OVERHEAD VALVE MEANS FOR INTERNAL COMBUSTION ENGINES Filed May 4, 1953 5 Sheets-Sheet 1 IN VENTOR ATTORNEY A. c. SAMPIETRO 2,744,513

May 8, 1956 v OVERHEAD VALVE MEANS FOR INTERNAL COMBUSTION ENGINES 3 Sheets-Sheet 2 Filed May 4, 1953 Fig.2.

I I I ATTORNEY y 8, 1956 A. c. SAMPIETRO 2,744,513

OVERHEAD VALVE MEANS FOR INTERNAL COMBUSTION ENGINES Filed May 4, 1953 3 Sheets-Sheet 5 L IN VENTOR M MM 23904 E M ATTORNE Y United States Patent OVERHEAD VALVE MEANS FOR INTERNAL COMBUSTION ENGINES Achille Carlo Sampietro, Detroit, Mich.

Application May 4, 1953, Serial No. 352,816

Claims priority, application Great Britain May 23, 1952 1 Claim. (Cl. 123-191) This invention relates to internal combustion engines, the object of the invention being to provide an improved engine arrangement which has the advantages inter alia of providing a compact structure.

According to the invention there is provided an internal combustion engine comprising at least one cylinder, said cylinder being of the type provided with a substantially hemispherical combustion chamber having on opposite sides thereof inlet and exhaust ports provided with poppet valves, wherein a single camshaft for operating said valves is provided on one side of said cylinder and is adapted to operate the valve on the said side by means of a push rod engaged by the camshaft and a rocker engaging the valve stem, and to operate the valve on the other side by means of a push rod engaging the camshaft, a first rocker arranged on the same side of the cylinder as the camshaft, a second push rod projecting across the cylinder head and a second rocker which is arranged on the other side of the cylinder and engages the stem of said other valve, one of said ports communicating with a lateral passage which projects between the push rods which engage the camshaft.

One construction of internal combustion engine in accordance with the invention, comprising a plurality of cylinders arranged in line, will now be described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a sectional view of the cylinder head of the engine, taken along the medial plane of the line of cylinders. The cylinder head cover has been removed from the left hand portion of this figure in order to illustrate the relative disposition of one set of rockers.

Fig. 2 is a sectional view of the cylinder head, taken through the center of one of the cylinders and at right angles to the medial plane of the line of cylinders.

Fig. 3 is a plan view of the cylinder head, the cylinder head cover being removed in the left hand portion of this figure, in order to illustrate the relative dispositions of both sets of rockers.

As shown in Figs. 1 and 2, each of the cylinders is provided with a hemispherical combustion chamber 1, the inlet port 2 and the exhaust port 3 being arranged on opposite sides of the medial plane of the line of cylinders, at an angle of approximately 45 to said plane. The inlet port 2 and the exhaust port 3 of each cylinder are provided with an inlet passage 4 and exhaust passage 5 respectively, both passages extending laterally i. e. substantially normally with respect to said plane. With the inlet port 2 there co-operates an inlet poppet valve 6 carried by a stem 7 which is slidable longitudinally in a valve guide 8 and which projects through the upper wall of the inlet passage 4. With the exhaust port 3 there co-operates an exhaust poppet valve 9 carried by a stem 10 which is slidable longitudinally in a valve guide 11 and which projects through the upper wall of the exhaust passage 5. The various inlet and exhaust valves are arranged to be operated from a single camshaft 25 which is arranged at one side of the line of cylinders and which actuates the valves through the intermediary of a suitable number of primary push rods 12. It will be understood that the two primary push rods 12 are associated with each cylinder, one primary push rod actuating the inlet valve and the other primary push rod actuating-the exhaust, and that all of said primary push rods 12 are arranged in a line on one side of the line of cylinders.- The primary push rods are disposed so that the'inlet passage 4 of each cylinder projects between the two primary push rods associated with the said cylinder.

A rocker shaft 13 is disposed above the valve stems 7 of the inlet valves 6 and carries a plurality of first rockers 14 and second rockers 15. The first rockers 14 are employed for operating the inlet valves 6 and each of these rockers 14 comprises second and first arms 16 and 17 respectively. The second arm 16 projects towards the cylinder axis and is engaged by a suitable one of the aforementioned primary push rods 12 and the first arm 17 engages the valve stem 7 of an inlet valve 6. The second rockers 15 each comprise second and first arms 18 and 19 respectively. The second arm 18 projects towards the cylinder axis and is engaged by a suitable one of the aforementioned primary push rods 12 and the first arm 19 projects towards the cylinder head and engages a secondary push rod 20 which extends from one side to the other of the associated cylinder across the cylinder head. The secondary push rods 20 cooperate with an equal number of third rockers 21 which are mounted on a rocked shaft 22 disposed above the exhaust valve stems 10, and which serve to actuate the exhaust valves 9. Each of the rockers 21 comprises second and first arms 23 and 24 respectively. The arm 23 projects away from the cylinder head and is engaged by one of the secondary push rods 20 and the arm 24 engages the valve stem 10 of one of the exhaust valves 9. The rocking axis of the first and second rockers are coextensive and the rocking axes of all three rockers lie within the angle bounded by two intersecting planes in which the axes of the valves 6 and 9 lie respectively.

In the above described arrangement the inlet passages project between the primary push rods, but if preferred the primary push rods and the camshaft may be mounted on the same side of the cylinders as the exhaust passages, which will then project between the primary push rods. Either arrangement provides a favorable passage for the inlet or exhaust gases as the case may be. Where, as in the case described, the inlet passages project laterally from the combustion chambers, there is the advantage, as

compared with an arrangement in which the said passages other side of said axis an exhaust port provided with a poppet valve, a single camshaft arranged at the same side of said cylinder axis as one of said valves, a first rocker mounted on the same side of said cylinder axis as said one valve with its rocking axis lying within the angle bounded by two intersecting planes in which the axes of the said poppet valves lie respectively, said rocker having a first arm for operating said one valve and a second arm which projects towards said axis, a first push-rod mounted for operation by said camshaft and engaging said second arm of said first rocker, a second rocker mounted on the same side of said cylinder axis as the said one valve with its rocking axis lying within the angle bounded by two intersecting planes in which the axes of the said poppet va yesli tc pe tiv y, a s con kc rh in a fi s arm which projects towards said cylinder head and a second arm which projectstowards said axis, a second PUShrIQd mounted for p r i y ;sa c mshaft and engag ng sa d sec rm of sa d s ndrqcke athin rocker; mounted on the same sideof saidaxisas-fihe other of, said valves with its rocking axis lyingwithinthea gle bounded by two intersecting planes in ,which theaxes of the said poppet valves lie respectively, said third rocker having a firstarm for operating said other valve and-a second arm which projects away from said cylinder head, and a thirdpush-rod extending across said cylinder head andengagingsaid firstarm of said second rocker and sgid second armpf said third rocker, said cylinder head being formed with a lateral passage which extends bet-ween 4 said first and second push-rods and provides communication between one of said ports and the exterior of said cylinder head.

References Cited in the file of this patent UNITED STATES PATENTS 1,621,326 Lawrence Mar. 15, 1927 2,253,034 Fiedler 'Nov. '18, 1 941 2,609,805 Pescara Sept. 9, 1952 2,650,578 Daub Sept. 1, 1953 FOREIGN PATENTS .438,838 GreatBritain N0v. 25, 1935 416,909 Italy Dec. 18, 1946 

